Histopathological and immunohistochemical evaluation of cellular response to a woven and electrospun polydioxanone (PDO) and polycaprolactone (PCL) patch for tendon repair

Mustafa Rashid,Stephanie G Dakin,Roberta De Godoy,Pierre-Alexis Mouthuy,Roger K W Smith,Mark Morrey,Andrew J Carr,Jayesh Dudhia,Sarah J B Snelling

doi:10.1038/s41598-020-61725-5

Abstract

We investigated endogenous tissue response to a woven and electrospun polydioxanone (PDO) and polycaprolactone (PCL) patch intended for tendon repair. A sheep tendon injury model characterised by a natural history of consistent failure of healing was chosen to assess the biological potential of woven and aligned electrospun fibres to induce a reparative response. Patches were implanted into 8 female adult English Mule sheep. Significant infiltration of tendon fibroblasts was observed within the electrospun component of the patch but not within the woven component. The cellular infiltrate into the electrospun fibres was accompanied by an extensive network of new blood vessel formation. Tendon fibroblasts were the most abundant scaffold-populating cell type. CD45+, CD4+ and CD14+ cells were also present, with few foreign body giant cells. There were no local or systemic signs of excessive inflammation with normal hematology and serology for inflammatory markers three months after scaffold implantation. In conclusion, we demonstrate that an endogenous healing response can be safely induced in tendon by means of biophysical cues using a woven and electrospun patch.

Highlights

Musculoskeletal disorders account for around 30% of all years lived with disability globally, and this is forecast to rise by 70% by 2030
In an attempt to address these issue we developed a synthetic biodegradable patch made of aligned electrospun fibers reinforced by a woven monofilament mesh[13]
The aims of this study were to investigate if a woven and electrospun PDO/PCL patch could safely induce a positive endogenous tendon fibroblast response and enable tendon repair in a non-healing large animal model

Summary

Introduction

Musculoskeletal disorders account for around 30% of all years lived with disability globally, and this is forecast to rise by 70% by 2030 Soft tissue disorders, such as tendon disease and tears, account for a significant component of this burden[1,2]. Artificial scaffolds have been employed in other clinical areas such as hernia repair and ligament reconstruction These patches may be made from synthetic polymers or based on modified human or animal extracellular matrix (ECM). In vitro studies demonstrate that electrospun scaffolds promote mesenchymal stem cell differentiation, tendon-derived cell attachment and cellular proliferation[17]. This spontaneous repair complicates evaluation of the efficacy of an augmentation strategy as the main objective is to induce a reparative cellular response. The aims of this study were to investigate if a woven and electrospun PDO/PCL patch could safely induce a positive endogenous tendon fibroblast response and enable tendon repair in a non-healing large animal model

Objectives

Methods

Conclusion